Abstract Theory and empirical patterns suggest a disproportionate role for sex chromosomes
in evolution and speciation. Focusing on ZW sex determination (females ZW, males ZZ; the …

Introgression, the incorporation of genetic material from one (sub) species into the gene pool
of another by means of hybridization and backcrossing, is a common phenomenon in birds …

Partial prezygotic isolation is often viewed as more important than partial postzygotic
isolation (low fitness of hybrids) early in the process of speciation. I simulate secondary …

We possess limited understanding of how speciation unfolds in the most species-rich region
of the planet—the Amazon basin. Hybrid zones provide valuable information on the …

Isolating barriers that drive speciation are commonly studied in the context of two‐species
hybrid zones. There is, however, evidence that more complex introgressive relationships are …

Hybrid zones occur as range boundaries for many animal taxa. One model for how hybrid
zones form and stabilize is the tension zone model, a version of which predicts that hybrid …

Hybridization is not always limited to two species; often multiple species are interbreeding.
In birds, there are numerous examples of species that hybridize with multiple other species …

Hybridization can serve as an evolutionary stimulus, but we have little understanding of
introgression at early stages of hybrid zone formation. We analyze reproductive isolation …

When a single species evolves into multiple descendent species, some parts of the genome
can play a key role in the evolution of reproductive isolation while other parts flow between …

Recent empirical studies have demonstrated that speciation with gene flow is more common
than previously thought. From a conservation perspective, the potential negative effects of …